In the areas of accident investigation, crime investigation, or crash forensics, forensic mapping is a critical tool and procedure for documenting a scene of interest and evidence contained therein. This is done to preserve the scene through forensic documentation for the purpose of determining and verifying the chain of events which occurred at a scene.
Conventionally, forensic mapping equipment is used to measure distances and angles at the scene, which typically include equipment similar to that used by a surveying team, such as a Total Station. This device is frequently employed by contractors, construction personnel, and surveyors as well. To those skilled in the art, this is known to be the most commonly used conventional surveying tool, wherein a first person operates the Total Station itself, and a second person, often known as a rod man, holds a rod with a reflector, occasionally referred to as a prism pole or simply ‘pole’. The first person with the Total Station is set up on a known reference point, and the second person moves to points of interest, whereby the Total Station may be used to ascertain coordinates, measurements of angles, and distance of and to the position that the rod man stakes out.
Conventionally, the Total Station must establish a level surface through the use of an adjustable tripod or other leveling device in order to facilitate accurate measurements. Additionally, the reflector must be held precisely plumb, or vertically perpendicular to the horizon. This must be done for each and every point of interest, and thus, it is a time consuming process. Frequently, the initial set up of this operation is the most time-consuming portion of the procedure. Occasionally, grass or high brush can interfere with the target acquisition portion of the procedure as well.
Many Total Stations have the ability to operate in two modes, the first being infrared, which requires a prism to reflect an infrared laser beam back to the Total Station in order to take a reading of the shot. The prism is mounted to a pole and held by an assistant (rod man). In order for the shot to be accurate, the prism pole must be held plumb. The other mode of a conventional Total Station is reflectorless, wherein a visible red laser is employed rather than an infrared laser. The visible red laser can be “shot” to any object within range and enough of the light is then reflected back to the total station for a reading to be taken. Some Total Stations are known to operate with only a visible red laser. These Total Stations are equipped with a switch to regulate between two modes: a reflector mode which uses low power, and a reflectorless mode which uses high power.
Unfortunately, it is generally accepted that it is even more difficult to perform this procedure at night without ample exterior ambient lighting. Additionally, it is known to be difficult for the second person to perfectly plumb the prism pole.
Thus, there is a need for a device that can quickly plumb the prism pole commonly employed by a Total Station and that can be adequately employed at night, where ambient lighting is minimal, saving the user's time, and expediting the process.
U.S. Pat. No. 7,215,412(B2) granted to O'Loughlin et al on May 8, 2007 is for “Flagpole Reflectors For Laser Range Finders.” While O'Loughlin teaches a prism pole that is similar to the present invention, it does not employ a self-plumbing agent capable of quickly plumbing the target, nor can it easily be adapted for use in low or no ambient light.
U.S. Publication No. US 2011/0032509 A1 published on Feb. 10, 2011 by Bridges is for an ‘Absolute Distance Meter With Optical Switch.’ Bridges teaches a distance meter designed to measure the distance to a target via an emitted light beam. Bridges varies from the present invention in that Bridges is designed to be a complete system for measuring distance alone, whereas the present invention is configured to facilitate and expedite the use of a conventional Total Station by placing the target of the light beam in a plumb state quickly, and with minimal effort.